Cable-controlled window winder with a guiding track

ABSTRACT

A cable window lifter for motor vehicles, with a guide rail, with a follower for a window pane which is mounted displaceable on the guide rail, and with a cable loop which is fixedly connected to the follower, in active connection with a drive unit, and is guided through guide pulley elements along the guide rail. The follower has a swivel mounted blocking element with a support area, preferably a support edge, which can be brought into positive locking engagement with a support element provided on the guide rail through swivel action of the follower. The support area of the follower associated with the support element is at a distance from the draw axis of the cable loop. The support element is mounted underneath the friction element. The window pane is in articulated connection with the follower.

FIELD OF THE INVENTION

The invention relates to a cable window lifter with a guide rail.

BACKGROUND OF THE INVENTION

With window lifters of this kind, the window pane is fixed on one or twofollowers which are each guided on a guide rail and which can bedisplaced along the guide rail by means of a cable loop in activeconnection with a drive for raising and lowering the window.

From DE 31 44 496 C2, a window lifter of the generic kind is known whichhas a hand or motor driven displacement drive and which preventsautomatic movement of the window pane when the displacement drive isstationary. This is achieved in that a brake device is attached to thefollower, which when the displacement drive is stationary, presses abrake block against a side face of the guide rail. When the displacementdrive is running, the guide rail is again released in that a resettingmember mounted movable on the follower moves the brake block into arelease position.

SUMMARY OF THE INVENTION

The object of the invention is to further develop a window lifter of thekind already mentioned so that a window can be held as securely aspossible in the closed position or another defined position with theminimum structural expense.

This is achieved according to the invention through a cable windowlifter for motor vehicles having a guide rail; a follower having aswivel mounted blocking element with a swivel axis; a cable loop whichis guided along the guide rail; and a friction element of the followerthat causes the swivel movement. The follower is mounted displaceable onthe guide rail and is in connection with a window pane. The swivel axisof the blocking element runs across the extension direction of the guiderail. The cable loop is in active connection through guide pulleyelements with a drive unit and transfers the drive force to thefollower. The friction element is in active connection with the guiderail and is mounted outside of a draw axis of the cable loop.

The blocking element of the follower has a support area, preferably asupport edge. This support area is movable from a first position spacedalong the draw axis of the cable loop from a support element provided onthe guide rail to a swiveled position that is in positive lockingengagement with the support element provided on the guide rail throughswivel action of the follower which is connected, for articulatedmovement, with the window pane. The support area of the follower isspaced from the support element along the draw axis of the cable loop.The support element is mounted underneath the friction element.

By friction element is meant a structural element which, duringdisplacement of the follower along the guide rail, experiences afriction force.

With the design of a cable window lifter, according to the invention,the uncontrolled opening of a closed window through external forceswhich can occur, for example, when travelling over uneven roads or inthe event of an unauthorized attempt to break into the vehicle, isprevented.

When an external force is exerted on the window pane which attempts tolower the window pane, a corresponding force also acts on the followerconnected to the window pane. Because the swivel mounted follower is infriction connection with the guide rail or another locally fixedcomponent part of the window lifter through a friction element, it doesnot simply follow the external force but it additionally executes aswivel movement about the axis which is defined by the friction element.

Because the friction element is preferably fixedly connected to thefollower, it is not a question of a locally fixed swivel axis. Ratherthe friction element and, thus also, the swivel axis follow the movementof the follower (time-dependent momentary swivel axis).

As a result of its swivel movement, the follower, during lowering of thewindow pane, comes to a stop with the support element which is mountedat a suitable point in the area of the guide rail. A further lowering ofthe window pane is then avoided through the alternating (positive)engagement of the follower and support element.

With the proper opening of the window pane by means of the window lifterdrive, the locking effect described above is prevented through suitablemeasures. The support element is mounted relative to the draw axis ofthe cable loop so that the cable loop during operation of the windowlifter forms a force component which counteracts the swivelling of thefollower.

Further measures exist in deactivating the support element duringoperation of the window lifter (e.g. through folding round) and/or insetting the friction force. The friction force acts in the area of thefriction element so that this friction force in comparison with the drawforces, which act during operation of the window lifter, only representsa slight disturbance which is not sufficient to release the blocking ofthe follower during proper operation of the window lifter and tensionedcable loop.

The optimum size of the friction force compared with the draw force canbe determined by experiment without problem for each type of windowlifter. The friction force can thereby very simply be varied by usingdifferent friction elements and/or by changing the force with which therelevant friction element is supported on the guide rail or similar.Typical values for the friction force are at about 5 N; the tensileforce of the cable loop amounts to about 400 N.

Insofar as the support element serves to hold the window pane assecurely as possible in its closing position, the support element ismounted so that when the window pane is closed, it is located near thefollower. The invention can however also be applied to secure otherdefined positions of a window pane.

The swivel movement of the follower takes place about an axis runningtransverse to the extension direction of the guide rail (guide directionof the follower). By this is meant, the axis of any swivel movement hasat least one component at right angles to the extension direction of theguide rail.

The friction element is mounted outside of the straight line which runsparallel to the draw axis of the cable loop and runs through theengagement point of the pane forces on the follower. The engagementpoint of the pane forces is defined by the position of connecting(fixing) elements of the window pane and follower and, as a rule, lieson the draw axis itself. Through the arrangement described of thefriction element, the direction of the swivel movement of the followercan be fixed by external forces and a reliable interaction with thesupport element can be ensured.

Furthermore, it is proposed to connect the friction element underneaththe fixing (connecting) elements for the window pane with the follower.

The friction element can be, in particular, a constituent part of thefollower, which is in frictional contact with the guide rail and whichis thereby supported on a base surface of the guide rail which runssubstantially parallel to the displacement plane of the window pane.

Furthermore, the friction element is preferably resilient and formed asan integral constituent part of the follower. The latter variation isparticularly expedient for plastics followers. However the frictionelement can also be a separate structural element which is inserted in asuitable socket of the follower.

The support element with which the follower is to engage during swivelmovement is mounted to secure the window pane in its closed position sothat it is located, when the window pane is closed, underneath thesection of the follower which can be brought into engagement with thesupport element. The phrase "mounted . . . underneath the . . .follower" is thereby to include any arrangement of the support elementrelative to the follower as a result of which the follower duringopening of the window is moved along the guide rail to the supportelement.

The follower should, however, when the window pane is closed, notdirectly adjoin the support element but be preferably spaced from thisalong the draw axis of the cable loop at least by a small gap; for therotary movement of the follower caused by the friction forces andproducing the positive locking action takes place, as a rule, at thesame time as the downward movement of the follower produced by theexternal forces. It is therefore possible that the follower then onlyconcludes its swivel movement, which is required for locking, when ithas already moved a little along the guide rail under the externalforce. When the window pane is closed, the distance between the followerand support element should however not be so great that the lockingmechanism first engages when the window pane has already released alarger gap relative to the window frame. The distance between thefollower and support element therefore preferably amounts to between 2mm and 10 mm.

The support element is preferably mounted on a side arm of the guiderail.

A particularly simple design is produced if the support element is anintegral constituent part of the guide rail. It can thereby be formedboth by a projection and by a recess of the guide rail.

In order to block the follower, the support element can have a stop facewhich runs inclined to the draw axis of the cable loop. A supportelement formed substantially triangular is particularly suitable forthis.

The said angle is selected so that on one hand, in the event of actionof external forces, the stop face blocks the follower reliably in apredetermined position, and that on the other hand the window pane,where necessary, can be opened at any time by means of the window lifterdrive and through the draw forces of the cable loop whereby the followerslides over the stop face.

When the cable loop is tensioned and the follower is extended along thedraw axis, the support element preferably reaches, in the directiontransverse to the draw axis of the cable loop, up to the follower. Itthereby happens that the follower contacts the support element as itpasses by. Depending on whether the lowering of the pane takes placethrough proper activation of the window lifter drive (thus with the drawforce of the cable loop) or through external forces acting on the windowpane, the follower either passes the support element or it swivelsagainst its stop face whereby the window pane is locked in keyedengagement in its actual position.

BRIEF DESCRIPTION OF THE DRAWINGS

Further advantages of the invention will become apparent from thefollowing explanation of various embodiments with reference to thedrawings in which:

FIG. 1 is a principle sketch of a cable window lifter;

FIGS. 2a and 2b show a follower with a friction element which is guidedin a profiled guide rail provided with a support element;

FIGS. 3a to 3c show a modification of the embodiment of FIG. 2 wherebythe follower is shown in three different positions along the guide rail;

FIGS. 4a to 4c show a principle sketch of a further modification of theembodiment of FIG. 2;

FIG. 5 shows an enlarged view of a cut-out section from FIG. 4b;

FIG. 6 shows a friction element integrated in one piece in a follower;and

FIGS. 7a and 7b show a separate friction element which can be insertedinto a follower.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 shows diagrammatically the known construction of a cable windowlifter.

A window pane 7 is connected on its lower edge to a profiled rail 8. AC-section 9 of the profiled rail engages the fastening elements of twofollowers 20. A cable pulley is associated with the followers 20 wherebya cable loop 1 which is in one piece or is composed of several cablesections is wound round a cable drum 3 of a drive unit 2 and is drivenby means of an electric motor (not shown) or a crank. The cable loop 1is guided through both an upper guide pulley 4 and a lower guide pulley5 along the guide rails 10 of the two followers 20. It can hereby beproposed that the cable loop 1 is guided at least in part in a Bowdentube.

The followers 20 are mounted to slide in the guide rails 10 and are eachconnected by a cable nipple 6 to the cable loop 1 so that duringactivation of the drive unit 2 the followers 20 are moved along theguide rails 10 between the guide pulley elements 4, 5. Because thefollowers 20 are connected on the other side to the window pane 7 by theprofiled rail 8, the window pane 7 is raised or lowered in side guides70 corresponding to the operation of the drive unit 2.

FIGS. 2 to 4 each show an embodiment of the present invention which canbe used with the cable window lifter described above and also with anyother cable window lifters having a guide rail.

According to the cross-sectional illustration in FIG. 2a and thecorresponding plan view in FIG. 2b, the cable window lifter comprises aprofiled guide rail 10 and a follower 20 which is fixedly connected to acable loop 1.

The guide rail 10 is formed hat-shaped in cross-section. It comprises alower base surface 12 which runs substantially parallel to the plane ofdisplacement of the window pane which is to be displaced (see FIG. 1).The guide rail is defined at the sides by two upwardly projecting arms13, 14. Guide sections 15, 16 protrude out from the side arms 13, 14 andeach define an upper base surface 17 and 18, respectively alignedparallel to the plane of displacement of the window pane.

The lower base surface 12 and the side arms 13, 14 form a guide channel11 in which a stud 21 of the follower 20 engages. The follower 20furthermore has, on both sides, hooked sections 25, 26. Each of thehooked sections engage round one of the guide sections 15, 16 of theguide rail 10. The hooked sections, together with the stud 21, provide akeyed connection between the follower 20 and the guide rail 10. Thekeyed connection is displaceable in the longitudinal direction of therail.

The follower 20, furthermore, has on its side, remote from the guiderail 10, a flat surface support element 22 which in a known way cansupport fasteners for the window pane 7, and a stop for defining thedisplacement path and the like. Here the fasteners for the pane 7comprise a plastics element 28, which on one side is connected witharticulated movement to the follower 20 by a ball bearing (fasteningpoint) 27 and on the other side is inserted in the C-section 9 of theprofiled rail 8. This articulated connection of the window pane 7 withthe follower 20 allows the follower 20 to swivel without the window pane7 turning.

According to the invention, the follower 20 is additionally providedwith a friction element 29 which is inserted in a socket (not shown inFIGS. 2a, 2b) of the follower 20 and which is mounted next to the drawaxis z of the cable loop 1. The friction element 29, whose constructionis shown in detail in FIG. 7a and 7b is in contact with the upper basesurface 17 of the guide rail 10.

If an external force sufficient to cause lowering of the window pane 7is exerted on the window 7, which is connected to the follower 20; e.g.,when travelling over uneven roads, after accidental release of the brakeof the window lifter or in the event of an attempt to open the window byforce from outside the vehicle, then this force also acts on thefollower 20 via the fastening point (ball bearing) 27. This entrainmentmember (the follower) is not only moved downwards along the guide rail10, but also at the same time swivels about a swivel axis, which isformed by the friction element 29, and runs transversely to the upperbase surface 17 of the guide rail 10.

It is thus not a fixed swivel axis but one which moves together with thefollower 20 when the follower slides down along the guide rail 10 underthe external force. Consequently, the position of the swivel axis istime-dependent (momentary axis), and depends on the external forceexerted on the follower 20. In each case a swivel movement of thefollower 20 is caused by the contact between the guide rail 10 andfollower 20 through the friction element 29. The swivel movement therebytakes place in one plane which runs parallel to the base surfaces 12, 17and 18 of the guide rail 10, i.e. the time-dependent swivel axis isaligned across this plane and thus across the plane of displacement ofthe window pane.

The swivel movement is thereby made possible in that both the stud 21and the guide channel 11, and also the hooked sections 25, 26 and guidesections 15, 16, each engage in each other with sufficient play; i.e.,the follower 20 is mounted in the guide rail 10 and able to swivelsufficiently.

As a result of the swivel movement described above, when the follower 20is lowered, a surface area 23 of the stud 21 stops at a stop face 31 ofa support element 30 formed on the side arm 14 of the guide rail 10. Thesurface area 23 is preferably a surface edge, a bottom underneath thestud. The follower 20 is thereby locked with keyed engagement in theguide rail 10, in that further lowering of the follower 10 anduncontrolled opening of the window pane which is connected to thefollower, is prevented.

Lowering of the follower 20 by means of the cable loop 1 and by means ofthe associated drive unit of the window lifter (see FIG. 1) is possibleas before, as will be described below with reference to FIGS. 3 and 4.

The construction of the guide rail 10 and the follower 20, in the caseof the embodiment of the invention shown in plan view in FIGS. 3a to 3c,agrees with the embodiment explained with reference to FIGS. 2a and 2bexcept for some geometrical deviations.

The following explanations are therefore restricted to the illustrationof further details on the function of the cable window lifter.

In FIG. 3a the follower 20 is located in its uppermost position in theguide rail 10; the associated window is closed accordingly. In thisposition, a support element 30 is formed along the extension directionof the guide rail 10, slightly spaced from the follower a distance a.The support element 30 is formed underneath the follower 20 on the sidearm 14 of the guide rail 10. The support element further projects as atriangular projection into the guide channel 11.

It can furthermore be seen from FIG. 3a that the cable loop 1 is relaxedunderneath the cable nipple 6 in the closed position of the window (withthe drive switched off). If in this situation an external force F_(a) isexerted on the window pane, which can occur for example when travellingover uneven roads, which acts through the fastening point 27 on thefollower 20 resulting in lowering of the follower 20, then the follower20 swivels about an axis lying transversely to the plane of displacementof the window pane. This axis is defined by the friction element 29mounted next to the draw axis z of the cable loop 1.

As shown in FIG. 3b, as a result of this swivel movement the underneath23 of the stud 21 travels, as the follower 20 drops down, to abut thestop face 31 of the support element 30. The stop face is inclined at anangle α of about 60° to the draw axis z of the cable loop 1. At the sametime, the follower 20 is supported at position (support area) 36 abovethe support element 30 on the side arm 13 of the guide rail 10.

(The support area 36 is located on the side opposite the support element30 of a plane running through the draw axis z of the cable loop 1 and atright angles to the plane of displacement of the window pane 7). Forcescan be introduced into the support area 36 which are substantiallyopposite those forces acting in the area of the support element 30.

By blocking the follower 20 in this way it is prevented from droppingdown further so that opening of the associated window is avoided. Thefollower 20 is locked in keyed engagement in the position shown in FIG.3b.

Since the follower 20 is also supported by the upper end of its stud 21on the side arm 13 of the guide rail 10 opposite the support element 30,the present locking mechanism is even self-locking relative to externalforces F_(a). If in this locked state of the window lifter, its drive isactivated to open the window and to lower the window pane, then the drawforce F shown in FIG. 3b acts on the follower 20. The draw force Fengages next to the draw axis z on the follower 20. The engagement pointof the cable loop 1 thereby lies on the same side as the support element30, which is next to the plane running through the draw axis z and atright angles to the plane of displacement of the window pane 7. (In thepresent example the draw force F actually engages in the area of thecable nipple 6; for greater clarity the force arrow F is however shownin the area of the underneath 23 of the stud 21).

The force F comprises a component F₂ parallel to the draw axis z as wellas a component F₁ transversely to same, whereby the latter causes theunlocking of the keyed connection. (Details for breaking down the drawforce F into components are apparent from FIGS. 4b and 5). The unlockingis due to the fact that the draw force F is much greater than thefriction forces both in the area of the friction element 29, and in thearea of the support element 30. The friction forces only represent aslight breakdown of the draw force F of the cable loop 1. The follower20 can therefore be unlocked under the action of the force components F₁(which act transverse to the draw axis z), whereby the follower is atfirst turned about the additional support area 36. The follower 20 isthen drawn together with the friction element 29 along the guide rail 10without the friction element 29 suffering any traceable resistance inview of the very large draw forces F (about 400 N).

FIG. 3c shows how the follower 20 moves downwards along the guide rail10 through the action of the draw force F. On passing the supportelement 30, the follower 20 is slightly off-set towards the arm 13 ofthe guide rail 10 opposite the support element 30 in order to escape thesupport element. For as can be seen from FIG. 3a, the support element 30projects somewhat further into the guide channel 11 than the distance ofthe follower 20 (with straight alignment along the draw axis z) from theside arm 14. Therefore the follower 20 contacts the support element 30in each case in the event of moving downwards from its closed positionillustrated in FIG. 3a.

Depending on whether the downward movement of the follower 20 takesplace through external forces F_(a) which act on the follower 20 abovethe friction element 29, or through draw forces F of the cable loop 1which engage on the follower 20 underneath the friction element 29, thefollower 20 does or does not swivel about the axis defined by thefriction element 29. In the former case the follower 20 is locked withkeyed engagement in its upper position; in the latter case the followercan escape the support element 30 (as explained with reference to FIG.3b).

The guide channel 11 is slightly wider than the stud 21 of the follower20 in the area of the support element 30, so that the stud can pass thesupport element 30 with slight play.

FIGS. 4a to 4c show a modification of the embodiment illustrated inFIGS. 3a to 3c. For clarity of the follower 20, only the stud 21 mountedin the guide channel 11 and the direction (friction) element 29 areshown diagrammatically. The stud 21 thus forms here at the same time asthe fixing element through which the follower is connected to the cableloop 1.

Two differences of the embodiment of FIGS. 4a to 4c from the embodimentshown in FIGS. 3a to 3c are as follows:

First, a support element 30' has here a recess 32 which is providedabove the stop face 31 and into which a part of the stud 21 of thefollower can swivel.

Second, formed at the bottom 23 of the stud 21 is an edge 24 facing thesupport element 30' so that this edge 24 during swivelling of thefollower can project into the recess 32. The edge 24 is thereby roundedwith a radius of curvature R which is of the same order as the distanced of the stud 21 from the side arm 14 of the guide rail 10 provided withthe support element 30.

In the state according to FIG. 4a, the follower (here represented by thestud 21) is located in its uppermost position in the guide rail 10, i.e.the associated window is closed. If in this state an external forceF_(a) acts on the window pane and, thus, on the stud 21 which leads toan uncontrolled lowering of the pane, then the follower swivels togetherwith the stud 21 about the friction element 29. The rounded edge 24 ofthe stud 21 thereby enters into the recess 32 of the side arm 14 of theguide rail 10. Simultaneously, the bottom 23 of the stud 21 abuts thestop face 31 of the support element 30' and an upper edge of the stud 21adjoins at the position 36 on the side arm 13 of the guide rail. Thefollower and window pane are thereby held self-locking in their upperposition, see FIG. 4b.

A secure locking of the pane through the swivel movement of the stud 21is thereby also ensured in that according to FIG. 4a, the supportelement 30' projects across the extension direction of the guide rail 10slightly further into the guide channel 11 than the distance d of thestud 21 from the side arm 14 provided with the support element 30'.

The stud 21 therefore contacts the support element 30' as the pane islowered from its uppermost position. A slight swivel movement about thefriction element 29 is then sufficient to make the desired positivelocking action.

On the other hand, the stud 21--and with it the follower and the windowpane fixed on the follower--can be lowered at any time in that asufficiently large draw force F is applied to the cable loop 1 by meansof the window lifter drive. See FIGS. 4b and 4c. The reasons for thishave already been explained above with reference to FIGS. 3b and 3c. Foran explanation of the draw force F acting in the area of the underneath23 of the stud 21 with the components F1 and F2 reference is made toFIG. 5 which shows a cut-out section of FIG. 4b.

FIG. 6 shows a friction element 29 which is formed as a roundedprojection integral on a follower 20. The friction element is infriction-locking spot contact with a base surface 17 of a guide rail 10whereby a swivel axis s is formed.

FIGS. 7a and 7b show a friction element 29 which forms a separatecomponent part which can be inserted in a suitable socket of a follower20. A friction element 29 of this kind is provided for example in theembodiments of FIGS. 2 to 4.

The friction element 29 comprises an elastic oval sleeve 42 of, forexample, metal in which a cylindrical structural element 41 of, forexample, rubber is mounted which practically completely fills out theoval sleeve 42 transversely to its longitudinal extension.

This friction element 29 is inserted in a follower 20 so that one of thebulging sections 45 of the sleeve 42 is in friction locking contact witha base surface of the associated guide rail 10.

Both with the embodiment according to FIG. 6 and with the exampleaccording to FIG. 7 the friction element 29 can, through itsfriction-locking contact with the guide rail 10, each time form an axisabout which the follower 20 is able to swivel.

We claim:
 1. A cable window lifter for motor vehicles comprising:a guiderail; a follower having a swivel mounted blocking element with a swivelaxis, which is mounted displaceable on the guide rail and is inconnection with a window pane; a cable loop which is guided along theguide rail, is in active connection through guide pulley elements with adrive unit and that transfers the drive force to the follower; and afriction element of the follower that causes the swivel movement and isin active connection with the guide rail; wherein the swivel axis of theblocking element runs across the extension direction of the guide rail,wherein the friction element is mounted outside of a draw axis of thecable loop; wherein the blocking element of the follower has a supportarea that is movable from a first position spaced along the draw axis ofthe cable loop from a support element provided on the guide rail to aswiveled position that is in positive locking engagement with thesupport element provided on the guide rail through swivel action of thefollower; wherein the support element is mounted underneath the frictionelement; and wherein the window pane is in articulated connection withthe follower.
 2. The cable window lifter according to claim 1 whereinthe friction element is in contact with a base surface of the guide railwhich runs substantially parallel to the plane of displacement of thewindow pane.
 3. The cable window lifter according to claim 1 wherein thefriction element is formed resilient.
 4. The cable window lifteraccording to claim 1 wherein the friction element is an integralconstituent part of the follower.
 5. The cable window lifter accordingto claim 1 wherein the friction element is a separate constituent partof the follower.
 6. The cable window lifter according to claim 1 whereinthe support element, when the window pane is closed, is locatedunderneath a support face of the followers; wherein the support face isassociated with the support element and can be brought into engagementwith the support element when the follower is swivelled.
 7. The cablewindow lifter according to claim 1 wherein the distance along the drawaxis of the cable loop is between 2 mm and 10 mm.
 8. The cable windowlifter according to claim 1 wherein the support element is mounted on aside arm of the guide rail.
 9. The cable window lifter according toclaim 1 wherein the support element is a constituent part of the guiderail.
 10. The cable window lifter according to claim 9 wherein thesupport element is formed at least in part by a projection of the guiderail.
 11. The cable window lifter according to claim 9 wherein thesupport element is formed at least in part by a recess of the guiderail.
 12. The cable window lifter according to claim 1 wherein thesupport element has a stop face for the follower which runs inclined tothe draw axis of the cable loop.
 13. The cable window lifter accordingto claim 1 wherein the support element has a substantially triangularshape.
 14. The cable window lifter according to claim 1 wherein thesupport element reaches up to the follower, in a direction transverse tothe draw axis, with straight alignment of the follower along the drawaxis of the cable loop.
 15. The cable window lifter according to claim 1wherein the support area is a support edge.
 16. The cable window lifteraccording to claim 1 wherein the support element is an integral part ofthe guide rail.
 17. The cable window lifter according to claim 1 whereinthe support element is formed at least in part by a projection of theguide rail.
 18. The cable window lifter according to claim 16 whereinthe support element is formed at least in part by a recess of the guiderail.